Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductor layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
Over the past several decades, the semiconductor integrated circuit industry has experienced rapid growth. Technological advances in semiconductor materials and design have produced increasingly smaller and more complex circuits. These material and design advances have been made possible as the technologies related to processing and manufacturing have also undergone technical advances. In the course of semiconductor evolution, the number of interconnected devices per unit of area has increased as the size of the smallest component that can be reliably created has decreased.
In integrated circuit devices, resistive random access memory (RRAM) is an emerging technology for next-generation non-volatile memory devices. RRAM is a memory structure including an array of RRAM cells each of which stores a bit of data using resistance values, rather than an electronic charge. However, although existing processes for manufacturing RRAM have generally been adequate for their intended purposes, as device scaling-down continues, they have not been entirely satisfactory in all respects.